NMR-based micrometabolic profiling of plant cells

Laser-assisted microdissection techniques are now widely accepted tools in various disciplines of plant science, including micrometabolic profiling (Hölscher and Schneider, 2008, Prog. Bot. 69, 141-167; Moco et al., 2009, J. Proteome Res. 8, 1694-1703; Fang and Schneider, 2014, Phytochem. Anal. 25, 307-313). We developed methods to analyze laser-microdissected samples by NMR spectroscopy and mass spectrometry. For example, cell-specific metabolic profiles of special cells harvested from the bark of Norway spruce (Picea abies) (Li et al., 2007, Planta 225, 771–779; Li et al., 2012, ChemBioChem 13, 2702–2713) were determined. Simultaneously, we reported laser-microdissection and NMR analysis of secretory cavities from fresh leaves and herbarium specimen of Dilatris plants (Haemodoraceae) (Hölscher and Schneider, 2007, Planta 225, 767–770). In such studies, the laser-harvested cells were transferred to a NMR tube and 1H and 2D NMR spectra were measured using a cryogenically cooled probehead. The structures of the major metabolites were identified by comparing NMR spectra of the cell extracts with those of authentic reference compounds. Further examples of combined laser-microdissection and spectroscopic analysis have been reported (Hölscher et al., 2009, Plant J. 60, 907-918; Happyana et al., 2013, Phytochemistry 87, 51–59; Fang et al., 2012, PloS One 7(10): e48006).